Reciprocity in Labor Relations: Evidence from a Field Experiment with Long-Term Relationships

We followed field workers administering a household survey over a 12-week period and examined how their reciprocal behavior towards the employer responded to a sequence of exogenous wage increases and wage cuts. To disentangle the effects of reciprocal behavior from other explicit incentives that occur naturally in long-term employment relationships, we devised a novel measure of effort that not only captures the notion of work morale but that field workers perceived as unmonitored. While wage increases had no significant effect, wage cuts led to a strong and significant decline in unmonitored effort. This finding provides clear evidence of a highly asymmetric reciprocity response to wage changes. Our estimates further imply that field workers quickly adapted to higher wages and revised their reference point accordingly when deciding on reciprocity. Finally, we consider a second measure of effort that was explicitly monitored and found no significant effect to any of the wage changes. This lack of impact illustrates that explicit incentives can easily outweigh the effects of reciprocity and highlights the importance of having a measure of effort that workers perceive as unmonitored when testing for reciprocity in long-term relationships.Reciprocity, gift exchange, efficiency wages, field experiment

Economic Growth, inequality and environment quality: An empirical analysis applied to developing and transition countries

This article aims at examining the relationship between social inequalities and pollution. On the one hand, it proposes a survey which shows that from a theoretical point of view, a decrease in inequality has an undetermined effect on environment. On the other hand, on the basis of these theoretical considerations, we propose an econometric analysis based on panel data for developing and transition countries during the period 1988-2003. More precisely, we examine the effect of income inequalities on the degree of local pollution (sulphur dioxide emissions and organic water pollution) by integrating Gini index in the formulation of environmental Kuznets curve. Then, two effects may be tested: (i) a direct effect of inequalities on pollution; (ii) an indirect effect by which the degree of inequality influence pollution by his negative impact on political freedoms.pollution; inequality; environmental Kuznets curve; panel data

Potentialités du Robinier en Wallonie

Le très controversé robinier (une bonne trouvaille pour les uns, une menace écologique pour les autres) fait l’objet de plusieurs études en Région wallonne, entre autres au sein de « l’accord cadre de recherche forestière » depuis 2000. L’objectif est de mieux connaître cette essence et son potentiel en sylviculture, et d’évaluer, à partir d’observations et de mesures réalisées au sein de nos peuplements régionaux, si les connaissances étrangères (hongroises surtout) peuvent être transposées à la Wallonie, comme cela a notamment été le cas dans le Fichier écologique des essences

Economic Growth, inequality and environment quality: An empirical analysis applied to developing and transition countries

This article aims at examining the relationship between social inequalities and pollution. On the one hand, it proposes a survey which shows that from a theoretical point of view, a decrease in inequality has an undetermined effect on environment. On the other hand, on the basis of these theoretical considerations, we propose an econometric analysis based on panel data for developing and transition countries during the period 1988-2003. More precisely, we examine the effect of income inequalities on the degree of local pollution (sulphur dioxide emissions and organic water pollution) by integrating Gini index in the formulation of environmental Kuznets curve. Then, two effects may be tested: (i) a direct effect of inequalities on pollution; (ii) an indirect effect by which the degree of inequality influence pollution by his negative impact on political freedoms.pollution; inequality; environmental Kuznets curve; panel data

Computing expectation values for RNA motifs using discrete convolutions

BACKGROUND: Computational biologists use Expectation values (E-values) to estimate the number of solutions that can be expected by chance during a database scan. Here we focus on computing Expectation values for RNA motifs defined by single-strand and helix lod-score profiles with variable helix spans. Such E-values cannot be computed assuming a normal score distribution and their estimation previously required lengthy simulations. RESULTS: We introduce discrete convolutions as an accurate and fast mean to estimate score distributions of lod-score profiles. This method provides excellent score estimations for all single-strand or helical elements tested and also applies to the combination of elements into larger, complex, motifs. Further, the estimated distributions remain accurate even when pseudocounts are introduced into the lod-score profiles. Estimated score distributions are then easily converted into E-values. CONCLUSION: A good agreement was observed between computed E-values and simulations for a number of complete RNA motifs. This method is now implemented into the ERPIN software, but it can be applied as well to any search procedure based on ungapped profiles with statistically independent columns

Numerical modelling of the sediment dynamics in Saint-Martin-la-Porte reservoir, France

Water Qualit

Local approach applied to the fracture toughness of resistance spot welds

International audienceA recently developed methodology for measuring the nugget fracture toughness in mode I was applied to three high-strength steel resistance spot welds, exhibiting either mixed cleavage/ductile or ductile fracture at room temperature. Fracture toughness tests revealed a difference in ductile-to-brittle transition temperature between the welds. Constitutive equations of weld nuggets were determined and implemented in a finite element model of the fracture toughness test, revealing both in-plane bending and in-plane stretching in front of the crack tip. Brittle cleavage fracture of the nuggets is not conveniently described using a simple Ritchie-Knott-Rice approach but the Rice-Tracey model allowed quantitatively relating the high number density of small particles to the nugget fracture toughness in the ductile regime

Nouvelles perspectives démographiques, mêmes défis budgétaires

L’Institut de la statistique du Québec (ISQ) a publié en juillet 2009 de nouvelles projections démographiques de la population québécoise. Or, sur la base des précédentes perspectives démographiques, nous avons, en 2007, tracé l’évolution des finances publiques du Québec d’ici 2051 en obtenant comme principal résultat que le rapide vieillissement de la population québécoise conduirait le gouvernement du Québec à l’impasse financière. Après avoir exposé les principaux changements découlant des nouvelles perspectives démographiques, la présente note de recherche mesure si ces nouvelles perspectives modifient sensiblement les résultats obtenus lors de la projection des finances publiques de 2007. Notre réponse à cette question est négative. Les nouvelles perspectives démographiques ne changent en rien nos perspectives budgétaires, laissant présager d’importantes difficultés financières.The Quebec Statistical Institute (ISQ) released in July 2009 new projections of Quebec population. Based on previous demographic scenarios, we projected in 2007 Quebec’s public finance until 2051. The budgetary deadlock of Quebec’s public finance due to the rapid population aging was our main finding. After presenting the main demographic changes of the revision, this research note measure whether or not these changes alter significantly the results of our 2007 projection. Our answer is no, as new demographic scenario unchanged budgetary problems facing the Quebec’s government